The present invention generally relates to a high tension terminal in an engine ignition apparatus to be directly connected with an ignition plug of an engine, and more particularly, to improvements in the engagement construction of the coil springs to be inserted into the interior of the high tension terminal.
Conventionally, an ignition apparatus of the engine is provided wherein a high tension terminal 2 is located within the high tension power source 1. Conductive coil springs 5 for or electrically connecting the high tension terminal 2 with the top terminal 4 of the ignition plug 3 are inserted into the interior of the high tension terminal 2, as disclosed within Japanese Patent Laid-Open Publication No. 3-47475.
The above described coil springs are required to engage the insertion end portion 5a with the high tension terminal 2 to an extent so that the coil springs may not naturally drop. As shown in detail in FIG. 18 (A), an annular engagement concave groove 2a is provided on the peripheral face of the cylindrical portion of the high tension terminal 2, and also, the outer diameter d1 of the insertion end portion 5a of the coil spring 5 is made larger in diameter (d1&gt;d2) than the outer diameter d2 of the coil spring 5. The insertion end portion 5a is inserted into the interior of the high pressure terminal 2 while the insertion end portion 5a is being contracted in diameter by the rotation in a reverse direction to the winding direction so that the insertion end portion 5a is adapted to be engaged with the engagement concave groove 2a. It was difficult to insert the insertion end portion 5a of a larger diameter than the coil spring 5 into the interior of the high tension terminal 2 so that the inserting operation was inferior. Also, it could not be visually recognized that the insertion end portion 5a of the coil spring 5 was engaged into the engagement concave groove 2a of the high tension terminal 2.
As shown in FIG. 18 (B), there is also a method of inserting the coil spring 5 into the interior of the high tension terminal with the inserting end portion 5a of the coil spring 5 being made the same diameter as the outer diameter d2 of the coil spring 2, thereafter drawing out, or inwardly projecting one portion of the outer peripheral wall of the high tension terminal 2, and engaging the insertion end portion 5a with the drawn out portions 2b, 2b.
When the insertion end portion 5a is engaged with the above described drawn out portions 2b, 2b, it is necessary to effect a drawing out working operation at another step after the insertion of the coil spring 5. When the bending of the inner portion side of the drawn out portion is small, and inconsistencies exist in the vertical direction of the spring, springs are often invisible through the gaps of the drawn out portion, with a problem that the spring engagement is hard to visually confirm from the outside.